Most scanning lidar systems provide only a single horizontal scan of data, from 180 degrees to 360 degrees. Newer lidar systems have added more lasers or mirrors to provide multiple scan lines of data, adding a vertical three-dimensional (3D) component to the data. Yet these 3D lidar systems are in general more expensive. Thus, it is starting to become more prevalent to take a single scanning lidar system and continually change the vertical tilt, to obtain the benefit of the added vertical dimension. However, this has previously been done in a very static way, allowing the user to choose the angular ranges and velocity at the beginning of a test but leaving those parameters untouched for the duration of the test. Moreover, these systems also do not usually allow for dynamically (during operation of the system) varying ranges or angular speeds. Thus, for prior art systems, if a region of interest shows up in the data or is identified by the user, all systems need to be closed down and restarted with new parameters for range and velocity.
Another old method currently used for viewing a large area as well as a smaller region of interest is to use multiple sensors. For this method, one sensor can view the larger picture while another sensor can focus on interest regions. This method can be difficult to maintain technically, mechanically, and financially. Additionally, such systems can present integration problems, in terms of fusing the pictures of separate sensors into one coherent overall image for the user.
In view of the above, it is an object of the present invention to provide a nodding mechanism for single-scan system that, when actuated, would allow for multiple horizontal scans at varying vertical angles to establish a 3D image for a 2D single-scan system. Yet another object of the present invention is to provide a nodding mechanism for single-scan system that allows the user to modify the sensor angular range and angular velocity remotely, which would allow the lidar data to be expanded to view a large area or condensed to view a smaller region of interest. Another object of the present invention to provide a nodding mechanism for single-scan system that allows for dynamic modifications of the angular range and velocity from a remote location, in response to the user's needs and the environment encountered by the sensor. Yet another object of the present invention is to provide a nodding mechanism for a single-scan system that can automatically adjust its angular nodding speed during operation of the device to account for terrain, detected objects, and the like, to establish a “smart” operation for the system. Still another object of the present invention to provide a nodding mechanism for single-scan system that can be backfit onto pre-existing robots having 2D single-scan systems. Another object of the present invention to provide a nodding mechanism for single-scan system that can be easily manufactured in a cost-effective manner.